Combining MicroElectroMechanical System (MEMS) and associated microcircuits or ICs (integrated circuits), such as drivers, onto a common substrate would produce significant advantages including, for example, higher channel counts. Unfortunately, the manufacturing processes for ICs and the MEMS devices are generally not compatible, and thus the direct integration of MEMS and microcircuit onto a monolithic substrate is challenging. Particularly challenging is integrating contact and metallization technology commonly used in microcircuit fabrication with high temperature processes of MEMS fabrication without compromising contact performance.
The current technology utilizes deep contacts formed after fabrication of the MEMS is substantially or entirely complete. This approach works but limits the minimum contact feature size due to the aspect ratio of the contacts. Conversely, a height or vertical stack-up of the MEMS is limited by the contact capability.